Light signal



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BY [[LS' ATTORNEY.

Patented June 12, 1934 PATENT OFFICE LIGHT SIGNAL Arthur E. Dodd, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application October 6, 1932, Serial No. 636,526

4 Claims. (01. 177-329) My invention relates to light signals, and has for an object the provision of a signal of the searchlight type wherein the indication may change from caution to proceed and vice-verse. *lwithout giving a momentary flash of the stop indication.

I Will describe one form of Signal embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a front view showing one form of signal embodying my invention. Fig. 2 is a side view of a portion of the signal shown in Fig. 1.

Similar reference characters refer to similar parts in each of the views.

Referring to the drawing, the signal comprises a polarized electromagnetic device made up of a neutral magnet M and a permanent magnet 5. The neutral magnet M involves the two usual cores 2 (one of which is directly behind the other in Fig. 1), each of which cores is provided with an operating winding 3 and an auxiliary winding 4 in inductive relation with the operating winding. The operating winding 3 is supplied with current from a battery 29 through a pole-changer 30 whereby the polarity of the current furnished to this winding may be re-' versed. In actual practice the two operating windings 3 on the two cores will be connected in series, but to simplify the disclosure the single operating winding shown in the drawing is con nected directly with the battery. Furthermore, the two auxiliary windings 4 on the two cores will usually be connected in series. The permanent magnet 5 is connected with the upper ends of the neutral magnet cores 2 by a backstrap 6 in the usual manner. The electromagnetic device also comprises a neutral armature 7 pivotally mounted at 8 and cooperating with the pole pieces 18 of the neutral magnet M. This device further comprises a polar armature 20 pivotally mounted at 19 in the pole piece 1''! of the permanent magnet 5 and cooperating with extensions 32 of the neutral magnet pole pieces 18. The armature 7 operates, among other things, a contact of the usual type involving a fixed contact member 35 and a cooperating contact finger 36 attached to a block 37 which in turn is fixed to the armature '7.

In order to prevent release of the neutral armature 'Yduring reversal of the polarity supplied to the operating winding 3, the electromagnetic device is provided with an auxiliary magnet K having a winding 25 connected with the secondary winding 4 of the neutral magnet M. In this case, as in the case of magnet M, the magnet will usually have two cores, one of which is directly behind the other in the drawing, and each core will have a winding 25, the two windings being connected in series. Cooperating with the pole pieces 26 of magnet K is an auxiliary armature 2'? which is attached to the neutral armature 7 by a bar 28. When the pole-changer 30 is reversed, thereby deenergizing and again energizing the operating winding 3, the current induced in the secondary winding 4 supplies current to winding 25 of auxiliary magnet K to prevent th neutral armature 7 from releasing.

Attached to the neutral armature 7 is a member 9 which is provided with a distinctively colored screen It adapted when in registry with a suitable source of light to cause the signal to indicate stop. This screen will usually be a circular piece of red glass. The source of light is a lamp L located at a point indicated in Fig. 1 but behind the parts shown in this view. The member 9 is also provided with a recess 31. This member 9 is so arranged that when the neutral armature 7 is in the attracted position the recess 31 is in front of the lamp L, so that the lamp is exposed in so far as this member is concerned, whereas when the neutral armature is in the released position, the screen R registers with the lamp.

A second member 10 is pivotally attached to member 9 at point 11 and is provided with two distinctively colored screens G and Y, adapted when in registry with the lamp L to cause the signal to indicate proceed and caution, respectively. These screens will usually be made of green and yellow glass, respectively. The member 10 is so arranged that the screens G and Y register with the recess 31 in member 9. The movement of the member 10 around its pivotal point 11 is limited by two stops 12 and 13 fixed to the member 9, and the parts are so arranged that when the member 10 engages the stop 12 the proceed screen G will register with the lamp L, whereas when the member 10 is in engagement with the stop 13 the caution screen Y will register with the lamp L, it being assumed, of course, in both instances that the neutral armature '7 is in the attracted position, so that the recess 31 in member 9 is in front of the lamp. The member 10 may be biased to its lowermost position in engagement with stop 12 by a spring 14, which is attached to the member 9 at point 15, and which bears downwardly against a pin 16 in the member 10. If desired, however, this biasing spring may be dispensed with and gravity alone may be depended upon to bias the member 10 to its lowermost position.

The member 10 is operated by the polar armature 20 through the medium of a link 22 pivotally connected with the member 10 at point 24, and a hook 21 attached to one end of the polar armature. This hook 21 engages a hook 22 at the upper end of link 22. The link 22 is restrained to move in a vertical path by a guide 23 attached to the member 9.

The operation of the signal is as follows: When the electromagnetic device is energized by current of what I will term normal polarity, the neutral armature 7 occupies its attracted position and the polar armature 20 is swung to the position shown in the drawing, so that the memher 9 is swung to the right, as shown in Fig. 1, and the member 10 occupies its lower position. Screen G then registers with the lamp L and the signal will indicate proceed. When the polarity of the current supplied to the operating winding 3 is reversed, polar armature 20 will be swung to the position opposite to that in which it is shown in the drawing, so that member 10 will be raised to its uppermost position, bringing the screen Y into registry with the lamp L; the signal will then indicate caution. When the operating winding 3 is deenergized by moving the pole-changer 30 to its middle position or by otherwise opening the circuit to this winding, the neutral armature 7 will release, thereby swinging the member 9 into such position that the screen R registers with the lamp L. The signal will then indicate stop.

t will be noted that during reversal of the polarity of the current supplied to the operating jwinding 3 the neutral armature 7 remains in its attracted position, so that when the indication given by the signal changes from proceed to caution or from caution to proceed, the stop screen R remains in the position in which it is shown in Fig. 1, with the result that no momentary flash of the stop indication is given by the signal.

The relationship between members 9 and 10, link 22, and hook 21, is such that should binding or excessive friction develop in the connections between these parts, no force can be exerted on neutral armature '7 in such direction as to hold this armature in the attracted position; and so this armature is always mechanically free to drop away and allow the signal to display the stop indication.

Although I have herein shown and described only one form of light signal embodying my in vention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A light signal comprising a polarized electromagnetic device having a neutral armature and a polar armature, a source of light, a me nber attached to said neutral armature and moved into or out of the path of light from said source according as the armature is attracted or released, said member having a distinctively colored screen which registers with said source when the armature is released and which then causes the signal to indicate stop, a second member having two distinctively colored screens arranged when in the path of light from said source to cause the signal to indicate caution and proceed respectively, said second member being pivotally attached to the first member in such position that when the neutral armature is attracted either the caution or the proceed screen may be in registry with said light source, means operating when said polar armature is swung in one direction or the other to move said caution or said proceed screen into registry with said light source provided said neutral armature is in its attracted position, and means for preventing said neutral armature from releasing when the polarity of the current supplied to said electromagnetic device is reversed.

2. A light signal comprising a source of light, a movable member having a distinctively colored screen which when in registry with said source causes the signal to indicate stop, said member being biased to such position that its screen registers with said source, means for moving said member to another position wherein the light source is exposed so far as such member is concerned, a second member provided with two distinctively colored screens which when in registry with said source cause the signal to indicate caution and proceed respectively, said second member being pivotally mounted on the first member in such manner that either the caution or the proceed screen may register with the light source when the first member is out of the path thereof, and means for moving said second member.

3. A light signal comprising a polarized electromagnetic device having a neutral armature and a polar armature, a member attached to said neutral armature and moved into or out of an indicating position according as the armature is attracted or released, said member having a distinctive screen which is displayed when the armature is released and which then causes the signal to indicate stop, a second member having two distinctive screens arranged when displayed to cause the signal to indicate caution and proceed respectively, said second member being pivotally attached to the first member in such position that when the neutral armature is attracted either the caution or the proceed screen may be displayed, means operating when said polar armature is swung in one direction or the other to move said second member into such position that its caution or its proceed screen is displayed provided said neutral armature is in its attracted position, and means for preventing said neutral armature from releasing when the polarity of the current supplied to said electromagnetic device is reversed.

4. A light signal comprising a movable member having a distinctive screen which when displayed causes the signal to indicate stop, said member being biased to such position that its screen is displayed, means for moving said member to another position wherein said screen is obscured, a second member provided with two distinctive screens which when displayed cause the signal to indicate caution and proceed respec tively, said second member being pivotally mounted on the first member in such manner that either the caution or the proceed screen may be displayed when the first member is in such position that its screen is obscured, and means for moving said second member.

ARTHUR E. DODD. 

